context_builder.go

/*
Copyright 2017 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package pretty

import (
	"fmt"

	"github.com/kubernetes-incubator/service-catalog/pkg/apis/servicecatalog/v1beta1"
	"k8s.io/apimachinery/pkg/apis/meta/v1"
)

// ContextBuilder allows building up pretty message lines with context
// that is important for debugging and tracing. This class helps create log
// line formatting consistency. Pretty lines should be in the form:
// <Kind> "<Namespace>/<Name>" v<ResourceVersion>: <message>
type ContextBuilder struct {
	Kind            Kind
	Namespace       string
	Name            string
	ResourceVersion string
}

// NewInstanceContextBuilder returns a new ContextBuilder that can be used to format messages in the
// form `ServiceInstance "<Namespace>/<Name>" v<ResourceVersion>: <message>`.
func NewInstanceContextBuilder(instance *v1beta1.ServiceInstance) *ContextBuilder {
	return newResourceContextBuilder(ServiceInstance, &instance.ObjectMeta)
}

// NewBindingContextBuilder returns a new ContextBuilder that can be used to format messages in the
// form `ServiceBinding "<Namespace>/<Name>" v<ResourceVersion>: <message>`.
func NewBindingContextBuilder(binding *v1beta1.ServiceBinding) *ContextBuilder {
	return newResourceContextBuilder(ServiceBinding, &binding.ObjectMeta)
}

// NewClusterServiceBrokerContextBuilder returns a new ContextBuilder that can be used to format messages in the
// form `ClusterServiceBroker "<Name>" v<ResourceVersion>: <message>`.
func NewClusterServiceBrokerContextBuilder(broker *v1beta1.ClusterServiceBroker) *ContextBuilder {
	return newResourceContextBuilder(ClusterServiceBroker, &broker.ObjectMeta)
}

// NewServiceBrokerContextBuilder returns a new ContextBuilder that can be used to format messages in the
// form `ServiceBroker "<Namespace>/<Name>" v<ResourceVersion>: <message>`.
func NewServiceBrokerContextBuilder(broker *v1beta1.ServiceBroker) *ContextBuilder {
	return newResourceContextBuilder(ServiceBroker, &broker.ObjectMeta)
}

func newResourceContextBuilder(kind Kind, resource *v1.ObjectMeta) *ContextBuilder {
	return NewContextBuilder(kind, resource.Namespace, resource.Name, resource.ResourceVersion)
}

// NewContextBuilder returns a new ContextBuilder that can be used to format messages in the
// form `<Kind> "<Namespace>/<Name>" v<ResourceVersion>: <message>`.
// kind,  namespace, name, resourceVersion are all optional.
func NewContextBuilder(kind Kind, namespace string, name string, resourceVersion string) *ContextBuilder {
	lb := new(ContextBuilder)
	lb.Kind = kind
	lb.Namespace = namespace
	lb.Name = name
	lb.ResourceVersion = resourceVersion
	return lb
}

// SetKind sets the kind to use in the source context for messages.
func (pcb *ContextBuilder) SetKind(k Kind) *ContextBuilder {
	pcb.Kind = k
	return pcb
}

// SetNamespace sets the namespace to use in the source context for messages.
func (pcb *ContextBuilder) SetNamespace(n string) *ContextBuilder {
	pcb.Namespace = n
	return pcb
}

// SetName sets the name to use in the source context for messages.
func (pcb *ContextBuilder) SetName(n string) *ContextBuilder {
	pcb.Name = n
	return pcb
}

// Message returns a string with message prepended with the current source context.
func (pcb *ContextBuilder) Message(msg string) string {
	if pcb.Kind > 0 || pcb.Namespace != "" || pcb.Name != "" {
		return fmt.Sprintf(`%s: %s`, pcb, msg)
	}
	return msg
}

// Messagef returns a string with message formatted then prepended with the current source context.
func (pcb *ContextBuilder) Messagef(format string, a ...interface{}) string {
	msg := fmt.Sprintf(format, a...)
	return pcb.Message(msg)
}

// TODO(n3wscott): Support <type> (K8S: <K8S-Type-Name> ExternalName: <External-Type-Name>)

func (pcb ContextBuilder) String() string {
	s := ""
	space := ""
	if pcb.Kind > 0 {
		s += fmt.Sprintf("%s", pcb.Kind)
		space = " "
	}
	if pcb.Namespace != "" && pcb.Name != "" {
		s += fmt.Sprintf(`%s"%s/%s"`, space, pcb.Namespace, pcb.Name)
	} else if pcb.Namespace != "" {
		s += fmt.Sprintf(`%s"%s"`, space, pcb.Namespace)
	} else if pcb.Name != "" {
		s += fmt.Sprintf(`%s"%s"`, space, pcb.Name)
	}
	if pcb.ResourceVersion != "" {
		s += fmt.Sprintf(" v%s", pcb.ResourceVersion)
	}
	return s
}